. >> reporter: eric smith heads the america's division of swiss re. >> reinsurance is about all forms of risk, whether its health, or life, or your home, or your property, the math behind it works the most effectively if you can spread the risk around the globe in all sorts of different forms. >> reporter: insurance companies buy their own insurance-- reinsurance-- from huge firms like swiss re which, because of their size, can afford the fullest data, plug in into the most sophisticated risk models. and doing just that, swiss re actually warned us of an east coast storm like sandy in 2006. after hurricane katrina, swiss re's head of catastrophe perils, andy castaldi, worried aloud about warming seas and more violent storms in the gulf. but, he told me: >> i'm also concerned about the new york bay and long island would be inundated by a flood, due to a category 3 storm. a storm surge could completely flood the airport at jfk. 13 feet of sea water is not out of or to 17 feet is not out of the question. >> reporter: so the blue is sandy's storm surge. we interviewed castaldi again last